I know of no other way to share access to a steem account except by sharing key access.
Keep in mind that on steempeak anyone with that account access gets to have access to all the templates and snippets that can be stored there.
But yeah i think there is a use case in connecting an account as the official account of the community. Perhaps it helps users to know which account to look to for official updates, maybe in the future a beneficiary system for that official account. etc
Yeah that is what we are doing now. I don't mind sharing the access to the templates, it is helpful for us to share and I trust our team. But it would still be nice to do it without having to share the private keys, by trusting their personal accounts for example.
That would be great if there could be official community account(s)!